Bone resorption acceleration and calcium reabsorption impairment in a Thai population with high cadmium exposure

Abstract

Some residents of the Mae Sot district in Thailand have suffered long-term exposure to elevated dietary levels of cadmium. To test the hypothesis that chronic dietary cadmium exposure can cause imbalance in calcium dynamics and accelerate bone resorption, a group of these residents (156 men and 256 women aged ≥ 50) were selected on the basis of previous records of elevated urinary cadmium and tested for urinary and blood cadmium, bone formation and resorption markers, and the renal tubular dysfunction markers. Both genders had high levels of blood and urinary cadmium and high urinary levels of the markers for renal dysfunction and bone resorption in a dose–response relationship to urinary cadmium. The excretion of bone resorption markers was positively correlated to the ratio of excreted calcium and urinary cadmium. The results of a multivariate regression analysis indicated that bone resorption was accelerated by impaired calcium reabsorption in renal tubules.

Keywords::

• Cadmium
• bone resorption
• calcium reabsorption
• Mae Sot

Acknowledgement

We thank all subjects for their participation. Thanks also to Dr Peter R. Hawkins for proofreading the manuscript and for his valuable comments. Kowit Nambunmee is studying for a Thai doctoral degree, funded by the Strategic Scholarship for Frontier Research Network of the Commission on Higher Education, Thailand. This work was funded by the Department of Public Health, Kanazawa Medical University, Japan.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.